Extracellular probiotic lipase capped silver nanoparticles as highly efficient broad spectrum antimicrobial agents

Area of Science:

• Environmental Science
• Nanotechnology
• Microbiology

Background:

• Antibiotic resistance is a growing global threat, necessitating the development of alternative antimicrobial agents.
• Silver nanoparticles (Ag NPs) are explored for their broad-spectrum antimicrobial properties, but environmental concerns exist regarding high-concentration usage.
• Probiotic-derived agents offer a potential avenue for developing safer nanomaterials.

Purpose of the Study:

• To synthesize and characterize silver nanoparticles (Ag NPs) stabilized by lipase from *Lactobacillus plantarum*.
• To evaluate the antimicrobial efficacy of these lipase-capped Ag NPs against key bacterial and fungal strains.
• To assess the safety profile of Ag NPs at concentrations below established toxicity limits.

Main Methods:

• Synthesis of Ag NPs using lipase from *Lactobacillus plantarum* as a stabilizing agent.
• Characterization of Ag NPs via UV-visible spectroscopy, FT-IR, ED-XRF, DLS, and HR-TEM.
• Antimicrobial activity testing against *Pseudomonas putida*, *Staphylococcus aureus*, and *Aspergillus niger*.

Main Results:

• Successful synthesis of lipase-capped Ag NPs with distinct characteristics confirmed by multiple analytical techniques.
• Demonstrated broad-spectrum antimicrobial activity of the synthesized Ag NPs against tested microbes.
• Effective antimicrobial action observed at concentrations significantly lower than the toxicity threshold in a zebrafish model.

Conclusions:

• Lipase-capped Ag NPs present a viable alternative for antimicrobial applications, addressing concerns of multi-drug resistance.
• The use of probiotic-derived lipase offers a potentially eco-friendly approach to Ag NP synthesis.
• These findings support the development of Ag NPs for safe and effective antimicrobial use at low concentrations.